The present invention generally relates to spray aerators and more specifically, but not exclusively, concerns a swivel type spray aerator that provides a clean appearance while allowing water to be diverted when the spray head is rotated in either direction.
Swivel spray aerators provide additional functionality to kitchen faucets as well as other types of faucets. The swivel spray aerators allow the user to swivel a stream of water over a greater area of a sink, which allows the sink and dishes as well as other objects, to be cleaned more thoroughly. Often times, swivel aerators have a spray function that provides additional cleaning power over the standard aerated stream. Typically, a diverter in the aerator is used to switch between the spray and aerated modes. Traditionally, swivel aerators have been designed as add-ons to an existing faucet, providing a functional but not aesthetically pleasing addition to the end of the faucet spout. This aesthetically displeasing design is in part due to the construction of the swivel sprays. An example of the construction of a typical swivel aerator 50 is depicted in FIG. 1. The swivel aerator 50 includes a ball stem 52 that is attached to the faucet spout and a swivel head 54 that swivels about the ball stem 52. As shown, the ball stem 52 has a neck 55 that is attached to a swivel ball 57, around which the head 54 swivels. An o-ring seal 59 is disposed between the swivel ball 57 and the head 54 so as to prevent water leakage. In order to provide the maximum coverage in a sink, the angle that the swivel head 54 is able to travel needs to be maximized. Generally, the size of the neck 55 of the ball stem 52 determines the limit of the angular travel of the head 54. The smaller the neck 55, the larger the angular travel. However, as apparent in FIG. 1, the smaller stem sizes cause the aerator 50 to look gangly and do not provide a smooth extension of the spout. In addition, to prevent the pinching of fingers, the neck 55 of the stem 52 is tapered, which increases its length and accentuates the small diameter of the neck 55 of the stem 52.
It is desirable to have some sort of shroud that would hide the small stem 52 so as to provide a smooth transition between the faucet spout and the swivel head 54. However, the introduction of the shroud can create a whole host of issues that can make its use practically infeasible. As an example, installing a shroud over the stem 52 would cause tolerance issues between the components in the swivel aerator 50 that would make mass production impractical. Either the clearance between the shroud and the swivel head 54 would be too small and the shroud would bind due to concentricity issues with the swivel ball 57, or the clearance would be so large to create a pinching hazard, in which the skin of the user's finger could be pinched between the shroud and the head 54. Another issue created by the use of the shroud concerns sealing the of the swivel aerator 50. Generally, most spherical ball seals, such as the seal 59 in FIG. 1, need to be pre-loaded in order to operate correctly. This pre-loading is accomplished by the swivel head 54 pushing on the swivel ball 57 from inside the wetted area, at location 60 in FIG. 1, so that the ball 57 is seated against the seal 59. However, the downfall with this type of seal configuration occurs when an attempt is made to shroud the exposed stem 52. If the shroud comes in contact with the swivel head 54, this contact unloads the seal 59, thereby causing a leak, and/or binds the assembly. To alleviate the leakage and binding problems, a larger gap between the swivel head 54 and the shroud would be required. As mentioned before, this large gap between the shroud and the swivel head 54 is unsightly and is a potential pinching hazard. Grime can also collect in the large gap, which in turn can create health and safety concerns.
Another issue with swivel spray aerators concerns the diverter that is used to switch between spray and aerated modes. Diverters generally fall into two categories, pull-down and twist type diverters. The pull-down diverter requires a protrusion or ring around the swivel head 54 of the aerator 50 to activate the diverter and requires a design that allows for linear travel of the protrusion. It should be appreciated that the protrusion or ring used to actuate the pull-down diverter can make the aerator 50 aesthetically less appealing. The twist type diverter does not have the above-mentioned aesthetic limitations, since its motion is in a rotational axis. However, twist type diverters can be difficult to operate since there is often no rotational limit on the swivel seal between the stem 52 and the head 54. This requires that a relatively large frictional force exist between the stem 52 and the swivel head 54 so that the diverter can be twisted without twisting the entire assembly. The swivel resistance or friction at the swivel has to be unusually high to compensate for the torque exerted on the diverter, and this higher resistance at the swivel makes swiveling of the head 54 more difficult. As should be appreciated, it would be desirable if the diverter motion was separated from the swivel motion so as to allow the two to operate independently. Moreover, in typical twist type diverters, the twisting motion is made at a location that is offset from the swivel motion such that the swivel head 54 can swivel out of position during twisting, thereby misdirecting the flow of water from the head 54. It would be advantageous for the swivel and diverter motions to operate about the generally same center of rotation, in so doing provide a better feel for the user. The range of motion of the twist diverter is also an area with room for improvement. The diverter often cycles one direction to switch for aerated and another direction for spray. There are often limits to the travel at each extreme. It would be advantageous if the twist diverter could be turned in either direction to change alternately between spray and aerator modes and have a full 360 degrees of rotation.
Thus, there is a need for improvement in this field.